When you multiclass 2 spellcasting classes does your focus work for all spells?

Druid wildshape, do you gain the beast’s abilities like pounce, pack tactics… ?

Book of the Tome Feature states you can take Cantrips from any classes spell list…

Would a Kenku’s mimicry of an instrument work?

If Kenku can’t speak, does that mean no spells with verbal components?

Do you have to declare Sneak Attack or Divine Smithe beforehand?